context menus won't show up for Opera 7.11 / 8.53+. It's not an Ext thing.
there's no way i know of to capture the right-click event in Opera. 8+
just fyi, jsakalos has implemented an alternative method of displaying context menus in Opera involving the use of a modifier key (the ALT key IIRC): http://aariadne.com/filetree
We are in 2010 and the version 10 of Opera still does the same thing...
I don't understand this developper choice because with FF, Chrome and IE this works well :-(
Also verify if "Preferences" -> "Advanced" tab -> "Content" menu -> "JavaScript options..." button -> "Allow script to receive right clicks" checkbox is set.